numpy.ma.masked_array.cumprod

masked_array.cumprod(axis=None, dtype=None, out=None)

Return the cumulative product of the elements along the given axis. The cumulative product is taken over the flattened array by default, otherwise over the specified axis.

Masked values are set to 1 internally during the computation. However, their position is saved, and the result will be masked at the same locations.

Parameters :

axis : {None, -1, int}, optional

Axis along which the product is computed. The default (axis = None) is to compute over the flattened array.

dtype : {None, dtype}, optional

Determines the type of the returned array and of the accumulator where the elements are multiplied. If dtype has the value None and the type of a is an integer type of precision less than the default platform integer, then the default platform integer precision is used. Otherwise, the dtype is the same as that of a.

out : ndarray, optional

Alternative output array in which to place the result. It must have the same shape and buffer length as the expected output but the type will be cast if necessary.

Returns :

cumprod : ndarray

A new array holding the result is returned unless out is specified, in which case a reference to out is returned.

Notes

The mask is lost if out is not a valid MaskedArray !

Arithmetic is modular when using integer types, and no error is raised on overflow.